diff --git a/js/src/jsscope.cpp b/js/src/jsscope.cpp
index b829f1b01cd4..5e3d42c2a6f0 100644
--- a/js/src/jsscope.cpp
+++ b/js/src/jsscope.cpp
@@ -139,7 +139,7 @@ JS_FRIEND_DATA(JSScopeStats) js_scope_stats = {0};
 
 # define METER(x)       JS_ATOMIC_INCREMENT(&js_scope_stats.x)
 #else
-# define METER(x)       /* nothing */
+# define METER(x)       ((void) 0)
 #endif
 
 bool